The NHS must find more than 1,000 extra school nurses to give the flu vaccine to healthy children under plans announced on Wednesday to expand the vaccination programme to all children aged two to 17.

Millions more people will be offered the vaccine, a nasal spray called Fluenz, under the scheme that is expected to run from 2014, the health secretary, Andrew Lansley, said. Options being considered to administer it include allowing parents to vaccinate their own children.

The decision follows a report from the government's advisers on vaccination policy, which drew on computer models to estimate that a 30% uptake of the vaccine could reduce deaths from seasonal influenza by 2,000 and lead to 11,000 fewer hospital admissions.

To meet the demand, advisers on the joint committee on vaccination and immunisation (JCVI) said the NHS needed several times as many school nurses, or others who could safely administer the spray, at least for the intense two-month period each autumn before the flu season begins. Schools in the UK currently have the equivalent of 1,168 full-time nurses.

The government is in discussions with the health regulator, the Medicines and Healthcare Products Regulatory Authority (MHRA), about whether parents, teachers and others trained by nurses can take on the role of administering the vaccine to children. "We are exploring all options at the moment," a spokesperson for the Department of Health told the Guardian.

David Elliman, a consultant in community health at Great Ormond Street hospital in London, said he had "immense concerns" about the resources needed to implement the plan, and criticised the JCVI for not making public the models used to arrive at the estimates.

"School nurses are already very hard stretched and come nowhere near delivering the basics from the Healthy Child Programme. If this is just added in to their workload, it will devastate their morale. If it is carried out by 'lay personnel' is this appropriate? Giving immunisations involves much more than just administering the vaccine, but counselling parents and, where appropriate, the young people. Lay people would not have the knowledge to do this," he said.

"I am not aware of large pools of professionals able to step in. In the past, school nurses have risen to the occasion, but that has been for a blitz in a single year or for a limited cohort. This is a very different kettle of fish," Elliman added.

The seasonal flu vaccine is already offered free of charge to the over-65s, pregnant women, and people who are particularly at risk, including those with diabetes and asthma. In expanding the programme, at a cost of more than £100m a year, the UK will become the first country to offer the flu vaccine free to healthy children.

Clare Gerada, chair of the Royal College of General Practitioners, welcomed the move and said that while the proposal meant extra work for GPs, flu vaccinations for pre-schoolers would fit in with existing child vaccination schedules.

"This is a sensible way forward and the sooner it happens the better. It will stop the confusion we saw last winter, when there was a call to immunise particularly the under-fives, and then the government said we shouldn't. Parents were confused by that. Now the guidance is clear-cut," she said.

Unlike the seasonal flu jab, the nasal spray contains a live, but weakened, strain of influenza virus, which causes a very mild flu infection. Typically, children younger than nine are given two doses in October or November, before the flu season starts. Millions of doses of the vaccine have been administered since it was first licensed in the US nearly a decade ago.

"Vaccination of healthy school children with the new nasal flu vaccine is a good idea as we know it's effective and safe, and flu can be a serious illness in childhood, not just in old age," said Adam Finn, professor of paediatrics at Bristol University.

"Although children don't die of flu as often as old people do, they can get sick enough to require hospitalisation. Many others are ill enough to require time off school which is disruptive for them and their families. Children also spread flu to other children and to adults including school staff and their families. Preventing flu in children should benefit all children and others too," he added.

In a statement, the chief medical officer, Professor Dame Sally Davies, said: "Severe winter flu and its complications can make people really ill and can kill, particularly those who are weak and frail which is why we already offer vaccinations to the most at risk groups. We accept the advice of our expert committee that rolling out a wider programme could further protect children, with even a modest take-up helping to protect our most vulnerable. There are significant challenges to delivering a programme that requires up to 9 million children to be vaccinated during a six-week period and we will look at the recommendations in detail to decide how best to develop and deliver the programme."